Elastin is an amorphous protein present in the elastic fibers of tissues such as arteries, blood vessels, skin, tendons and elastic ligaments, the abdominal wall, and lungs. Unlike other fibrous tissues like collagen, elastin is unique in that it may be stretched to over 150 percent of its original length but it can rapidly return to its original size and shape. This property of elastin provides tissues that incorporate it the ability to resume their original form after stretching due to, for example, blood flow, breathing, or bending. Like collagen protein, elastin contains about 30% glycine amino acid residues and is rich in proline. Elastin differs from collagen in that it contains very little hydroxyproline or hydroxylysine. Elastin has a very high content of alanine and also contains two unique amino acids isodesmosine and desmosine. These amino acids are believed to be responsible for elastin's ability to return to its original shape after stretching.
A lack of elastin or genetic abnormalities affecting elastic fibers in skin, as evidenced in Costello Syndrome, Cutis Laxa and Pseudoxanthoma Elasticum, for example, lead to premature aging most noticeably characterized by wrinkling and folding of the skin in children (pre-teenage) suffering from these illnesses. Given that these conditions only affect elastic fibers in skin, it is highly probable that development of wrinkles in aged skin is due to damage to or loss of elastic fibers in skin. Unfortunately, dermal fibroblasts lose their ability to make elastin (the major component of elastic fibers) by the end of puberty. Hence, adult dermal fibroblasts cannot repair or replace damaged elastic fibers in skin later in life, leading to an essentially irreversible formation of wrinkles.
The protein motif VGVAPG (SEQ ID NO. 1) has been previously shown to stimulate proliferation/migration of monocytes, dermal fibroblasts, and smooth muscle cells through its interaction with the cell-surface elastin receptor. Other GXXPG (SEQ ID NO. 2) sequences recognized by BA4 antibody are also known ligands for the elastin receptor. More recently, it has been shown that elastin peptides, liberated through proteolytic digestion of bovine ligamentum nuchae and containing elastin receptor ligand sequences (GXXPG) (SEQ ID NO. 2) also induce elastogenesis in dermal fibroblasts through interaction with the elastin receptor.